: Just bought a 98 Deville, was overheating, am I paranoid?

09-25-09, 09:19 PM
Ok, this is my first post here but let me know say I have been an avid reader of this website for months. I recently had been thinking of buying a Lac and this website gave me some of the best info available on the net period, just reading some threads here were very useful and better then any info I got calling a shop.

Now with that said, I recently purchased a 98 Deville from a private dealer, checked out the car, test drove it and it ran as smooth as possible, it's no exaggeration to say this car ran like a 2008.. He said he installed a new transmission, belts, hoses, etc etc, lots of work under the hood, so while the interior wasn't as nice as some I'd seen I opted to go for under the hood vs appearance which I like to do myself anyway.

The 1st bad sign/feeling I got was that I called him later that night to ask a question about the car and his number was disconnected immediately, not even 30 minutes after I purchased the car. How does that happen? Then the 2nd day I drove it to work it started to overheat and the 'service engine' light popped on and I started to panick immediately thinking it had to of been a head gasket. Well after some further inspection the car was really low on oil AND coolant, so I got the oil changed high grade and added just a SMALL amount of Dex antifreeze.

Note that I didn't want to over do it with the coolant because I wasn't sure if it was ok to add the whole bottle without flushing or draining the radiator 1st(will do so in about a month but funds are tight now). Weird thing was after all that the service engine light was STILL on. The day it overheated it ran up to almost 250 by the time I got home, this time on the way home it never got above 210 until I stopped at the gas station and left it running so it went up to 216, then when I pulled off back down to low 200, no overheating, so basically it seemed ok but still the engine light was on.

So after further research, I found the codes to take off the 'check engine' light and that worked. But I felt like it wasn't that big of a deal because on the dash it's also blinking check oil and check coolant, which are both full, so I thought it had to be an elic. problem somewhere.

Now my question is, will turning off that check engine light end up biting me in the ass? The car runs great, no leaks, no smoke, no overheating at all...I didn't know if this was a normal problem, or if I'm a week or month away from a bigger problem. I really want to enjoy my car but getting to work is a necessity so I'd have no problem selling it for a $700 reliable Grand Am that runs, I've just heard how bad these electrical problems can be.

Also, without flushing or draining my radiator, is it ok to add the full bottle of Dex Cool? I haven't even used half yet because I wasn't sure, but I know it needs more then what I have. I'd really hate it if I turned off the check engine light to another problem then one day it just gets extremely worse...Also the fact that he ended up changing his # so abruptly has left a very bad taste in my mouth ever since.

Appreciate any help you guys could give me. It's totally possible I'm freaking out over reading all these head gasket threads, and mechanics are charging an arm and a leg just to take a look at the car so that's not an option now. Just need a few opinions/suggestions.

Sorry for so long, just wanted to give as much info as possible, any help would be greatly appreciated.

edit: also forgot 2 note...Mileage is 159k

09-26-09, 01:20 AM
Welcome to the forum.

The forum archive has a wealth of information available at your finger tips.
Please read the "Sticky: How To Pull Codes (http://www.cadillacforums.com/forums/northstar-performance-technical-discussion/53635-how-pull-codes.html) "

Pull any code you have and see what else may have trigger the check engine light.


09-26-09, 09:51 AM
The reason those lights are on is because the coolant is low. Add whatever you need to bring it up to the halfway point in the surge tank. If you need that much, there is a problem. You have to figure out where it is going.

The oil light is on because at 250 deg. you cooked the oil and it needs to be changed.

With the problems you are having and the phone being disconnected right after the sale, I smell a rat. Might want to have the coolant tested for the presence of exhaust gases or rent a tester and do it yourself.

09-27-09, 01:33 AM
Pull the codes, no harm done doing so :D

You need to know what codes its throwing to further your knowledge on what is happening with the car